Cell Biology - Cell structure

Question 1

What type of cells are eukaryotic?

Answer 1

Plants, animals, protists and fungi.

Question 2

How big are eukaryotic cells?

Answer 2

10-100 micrometres.

Question 3

What are the properties of eukaryotic cells?

Answer 3

• Unicellular = single-celled.

- Have DNA that forms chromosomes in a nucleus.

Question 4

What type of cell is prokaryotic?

Answer 4

Bacteria.

Question 5

How big are prokaryotic cells?

Answer 5

0.1-5 micrometres.

Question 6

What are the properties of prokaryotic cells?

Answer 6

-Small rings of DNA called plasmids.
-Unicellular = single celled.
-Single DNA loop in cytoplasm (where DNA is stored).
-No mitochondria or chloroplasts.
No nucleus.

Question 7

What sub-cellular structures do prokaryotic cells have?

Answer 7

• Cell wall.
• Cytoplasm.
• Cell membrane.
• Flagellum.
• Bacterial DNA loop.
• Plasmid DNA rings.

Question 8

What do all plant and animal cells have?

Answer 8

• Cell membrane.
• Nucleus.
• Mitochondria.
• Ribosomes.
• Cytoplasm.

Question 9

What sub-cellular structures do all plant cells have that animal cells don’t?

Answer 9

• Permanent vacuole.
• Chloroplasts.
• Cell wall.

Question 10

What is the function of the cell membrane?

Answer 10

Controls what substances move in and out of the cell.

Question 11

What is the function of the nucleus?

Answer 11

Contains the cells DNA.

Question 12

What is the function of ribosomes?

Answer 12

Site of protein synthesis.

Question 13

What is the function of mitochondria?

Answer 13

Where energy is released through aerobic respiration.

Question 14

What is the function of cytoplasm?

Answer 14

Jelly like substance where chemical reactions take place.

Question 15

What is the function of the permanent vacuole?

Answer 15

Stores water and contains cell sap.

Question 16

What is the function of chloroplasts?

Answer 16

Contains chlorophyll for photosynthesis.

Question 17

What is the function of the cell wall?

Answer 17

Made of cellulose, which strengthens the cell.

Question 18

When do animal cells differentiate?

Answer 18

Early on in their development.

Question 19

When do plant cells differentiate?

Answer 19

All throughout its lifetime.

Question 20

What are the 3 steps of taking plant cuttings for plant cells to differentiate?

Answer 20

-Cut small section off a plant stem.
Plant the cut section.
-Some cells differentiate and create a new root tissue.

Question 21

Why do animal’s cells divide?

Answer 21

• Replace cells.

- Repair tissues.

Question 22

What is the function of the specialised sperm cell?

Answer 22

Fertilise an egg.

Question 23

How are sperm cells adapted?

Answer 23

• Tail to swim to egg.
• Acrosome at tip of head (contains enzyme to penetrate egg).
• Half DNA of organisms genetic material.
• Mitochondria for energy to swim to egg.

Question 24

What is the function of the specialised red blood cell?

Answer 24

To transport oxygen around the body.

Question 25

How are red blood cells adapted?

Answer 25

- No nucleus- more room for oxygen. | - Contains haemoglobin that binds to oxygen molecules.

Question 26

What is cell differentiation?

Answer 26

When a cell gains new sub-cellular structures in order to perform a specific function. The cell them becomes specialised.

Question 27

What is the function of the specialised muscle cell?

Answer 27

To contract and relax to allow movement.

Question 28

How are muscle cells adapted?

Answer 28

- Contains protein fibres that can contract to allow movement. - Contains mitochondria to release energy.

Question 29

What is the function of the specialised nerve cell?

Answer 29

To carry electrical impulses around the body.

Question 30

How are nerve cells adapted?

Answer 30

- Have a long axon to increase the distance electrical signals can travel. - Have dendrites (branched endings) to make connections with other neurones. - Myelin sheath insulates the axon and stops electrical nerve signals leaking out the cell, increasing the transmission speed of the electrical impulses.

Question 31

What are gaps between neurones called?

Answer 31

Synapses.

Question 32

What is the function of the specialised root hair cell?

Answer 32

To absorb mineral ions and water from the soil.

Question 33

How are root hair cells specialised?

Answer 33

- Long projections that increase the surface area that the plant can use to absorb more water and minerals. - Mitochondria to release energy for the active transport of mineral ions.

Question 34

What is the function of the specialised palisade cell?

Answer 34

To enable photosynthesis in the leaf.

Question 35

How are palisade cells adapted?

Answer 35

- Lots of chloroplasts containing chlorophyll to absorb light energy. - Located at top of surface of leaf to absorb the most light energy.

Question 36

What is the equation to find magnification?

Answer 36

Magnification= image size / actual size

Question 37

What does magnification tell us?

Answer 37

How many times larger an image seen through a microscope is compared to the real object.

Question 38

Define resolution

Answer 38

The ability to distinguish between two or more objects that are close together.

Question 39

What do light cells allow us to do?

Answer 39

Distinguish between types of cells.

Question 40

What do electron microscopes allow us to see?

Answer 40

Sub-cellular structures - ribosomes, mitochondria etc.

Question 41

What are advantages of light microscopes?

Answer 41

- Cheap. | - Living samples can be seen.

Question 42

What are the disadvantages of light microscopes?

Answer 42

- Low magnification. | - Low resolution.

Question 43

How do light microscopes work?

Answer 43

Uses light to form images.

Question 44

What are the advantages of electron microscopes?

Answer 44

- High magnification. | - High resolution.

Question 45

What are the disadvantages of electron microscopes?

Answer 45

- Samples cannot be living. | - Expensive.

Question 46

How do electron microscopes work?

Answer 46

Uses a beam of electrons to form images.

Question 47

What are the steps of completing a light microscope experiment?

Answer 47

1 Put a thin sample of tissue onto a microscope slide. 2 Add a few drops of suitable dye/stain. 3 Place a coverslip on top of the tissue and place the slide onto the microscope stage. 4 Use the objective lens with the lowest magnification and focus on the sample. 5 Increase the magnification and refocus to see different features of the cell.